A former high-flying Auckland businessman died after his unattended leg wound became infested with maggots.

Lance Bain, an alcoholic, received a cut to his shin on November 17, 2011 after he was attacked with a rubber mallet by his former partner Natalie Van Breugel, 45, also known as Natalie Reader.

Van Breugel was originally charged with manslaughter but she pleaded guilty today after the charge was dropped to wounding with intent to injure.

Bain was drunk and in bed at his Ranui, West Auckland, home when he was attacked. Van Breugel took to him because he had sold her car without her knowing and she had read some text messages on his phone to other women that she objected to.

She beat him up and down his body with the mallet, which is normally used for hammering in tent pegs, causing bruising and the wound to his leg.

He left the house and was later stopped by police who booked him for drink driving. They offered him treatment for his leg, which he refused.

He drank his way through his illness and was admitted to hospital 11 days later with his leg wound infested with maggots.

He died of sepsis on December 3.

After Bain died, the coroner asked police to investigate the chain of events that led to his death.

It is understood Van Breugel and Bain were in a relationship.

Bain's Linked In profile listed him as senior advisor and consultant for Bain Group Property, Vehicle and Investment Consultants.

It listed his previous job as director of Paritai Car Consultants, Paritai Drive.

It's understood he owned property in the area but shortly before his death had suffered major financial loss.